where \(c\)  is the coupling coefficient, \(u=W\cdot v_{p}\) . \(v_{p}\)  is the output of the primary capsule layer. For dynamic routing, we first set the agreement \(b\)  to 0. The coupling coefficient \(c\)  can be calculated by \(c = softmax(b)\) . That is to say, we update \(b\)  to calculate the latest coupling coefficient \(c\) . In addition, the update process of \(b\)  can be expressed as \(b\leftarrow b+u \cdot v_c\) . The detailed descriptions of the dynamic routing can be found in [1]}.
